Rehabilitation of the Hsi-Lo Bridge in Taiwan

The Hsi-Lo Bridge spans the Cho-Shui River in central Taiwan and has suffered from scour in recent decades since its construction in 1946. Many caisson foundations of the bridge were precariously exposed. To preserve this well-known Taiwan landmark, the client attempted to retrofit the substructure. Several important issues including seismic, hydraulic and geotechnical considerations were examined. After considering a number of proposals, a retrofit strategy to completely replace the substructure was selected. An auxiliary substitution member was adopted to strengthen the superstructure. The temporary steel frame as well as the bearing system was carefully designed to support the superstructure during construction. A specially designed joint was proposed for the adjustment of the probable eccentricity of main columns. The retrofit project was daunting in its complexity, but proceeded without incident due to meticulous planning and designing.